Hydrothermal synthesis of inorganic nanoparticles for potential technological applications : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at Massey University, Manawatū, New Zealand

Figures are re-used with the publishers' permission.Iron oxide nanoparticles (IONPs) are of interest in a diverse range of environmental and biomedical applications due to their intrinsic chemical, physical and thermal features such as superparamagnetism, high surface-to-volume ratios, high biocompatibility, low toxicity and easy magnetic separation. Many technological applications necessitate small (diameter < 20 nm) nanoparticles with narrow size distributions (< 5 %) and pronounced saturation magnetisation (Ms) for uniform physical and chemical effects. Historically, the synthesis of IONPs with controlled size and size distribution without particle agglomeration has proved challenging. In this thesis, we utilised an easy hydrothermal route and successfully synthesized two common phases of IONPs, namely Fe₃O₄ (magnetite) and α-Fe₂O₃ (hematite), using Fe(acac)₃ as iron source. By controlling the reaction conditions such as time, temperature, and the concentration of surfactants such as PVP and oleic acid, the different phases were selectively synthesized. The prepared nanoparticles were fully characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), energy dispersive X-Ray spectroscopy (EDS), atomic absorption spectroscopy (AAS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating-sample magnetometry (VSM), Brunauer-Emmett-Teller (BET) surface area measurements, photoluminescence (PL) and UV–Vis diffuse reflectance spectroscopy (UV–Vis/DRS). In Part I of this thesis, Fe₃O₄ and metal-doped spinel MxFe₃−xO₄ (M = Fe, Mg, Mn, Zn) nanoferrites were synthesised as agents for cancer treatment via a method called magnetic fluid hyperthermia (MFH). In Part II, α-Fe₂O₃ nanoparticles were hybridized with tin (II) sulfide (SnS) to create p-n heterojunction photocatalysts for efficient H2 production via ethanol photoreforming

Modeling Accounting Profit Behavior Based on Events Theory a Comparative Study of Companies Listed on the Tehran and Istanbul Stock Exchange

Purpose: Th is study aims to evaluate the effect of annual financial events on operating, and net accounting profits in the financial statements of Iranian and Turkish companies. &nbsp; &nbsp;Theoretical framework: The profitability of the company is one of the main factors that determine shareholder and investor returns. This topic has been central to a number of contemporary financial studies discussed in the literature review. &nbsp; Design/methodology/approach: To conduct the research, data related to the financial statements of 121 companies listed on the Tehran Stock Exchange for a period of 10 years from 2010 to 2019 and 151 companies listed on the Istanbul Stock Exchange for a period of 10 years from 2010 to 2019 were used. &nbsp; Findings: According to the results, there was a significant relationship between financial events and operating, and net accounting profits of Iranian and Turkish companies. Moreover, current and previous financial statements affected accounting profit, and no significant difference was observed between the two geographical locations of Iran and Turkey. &nbsp; Research, Practical &amp; Social Implications: Information about companies' financial statements could be utilized by investors and analysts to more suitably analyze companies' current and future profits and returns. &nbsp; Originality/value: Most previous studies have assessed factors inside or outside the organization affecting profit, and the capacity of complete information on the change of the financial situation in different periods and its effect on profit behavior has not been thoroughly analyzed. This matter highlights the significance of our study

Investigating the influencing factors on trust and professional skepticism in the relationship between the auditor and the client firms’ managers

The current study investigates how interpersonal trust between the auditor and the client firms’ managers affects the auditor's professional skepticism in Iraq. In the qualitative part of the research, 20 auditors and client firms’ managers were interviewed. In the qualitative section, the interviews conducted were analyzed using MAXQDA software. The statistical population includes two groups: all auditors, 1735 participants until the end of 2022, and all senior managers and managers of public companies, private companies, and other organizations. The statistical sample size is 314. The data collection instrument was Aschauer et al.'s (2017) questionnaire, which was analyzed using PLS3 software. The findings support the idea that there is a positive correlation between the degree of skepticism towards the auditing profession and the degree to which corporate managers and auditors are trusted. Perceived trust between auditors and managers and skepticism of auditors' professions are not significantly correlated with the length of the auditor's contact with the client. The relationship between auditors' and managers' trust in them and their skepticism of the auditing profession is not also significantly impacted by the supply of non-audit services

Proposing a model for the effect of performance-based budgeting on the qualities of higher education in Iraq

Nowadays, rivalry can be observed not just between businesses, but also between universities. Higher education institutions have been under increasing pressure from external factors including labor and education market rivalry to improve the quality of their programs by reevaluating their organizational structures and management practices. This study set out to determine how performance-based budgeting would affect the quality of Iraq's postsecondary institutions. The statistical subjects of this study are those involved in performance-based budgeting in Iraqi universities, including the deans of the faculty and deputy deans, the director of the accounting department, and the financial and accounting staff. Morgan's table suggests a minimum sample size of n=246. This is because 3519 individuals were sampled from the population of non-professional private higher education institutions in Iraq. A total of 198 completed surveys were submitted. The collected data from the questionnaire was analyzed using a structured equation model. The results indicated that performance-based budgeting benefited greatly from considering organizational commitment and rewards mechanisms. The results, however, showed that the competence of managers played no impact in the introduction of performance-based budgeting in Iraq's higher education sector. However, the results showed that performance-based budgeting had no effect on the quality of higher education in Iraq, and neither did the competency nor the organizational commitment of managers in these institutions, nor did reward schemes

Intravenous Amiodarone versus Digoxin in Atrial Fibrillation Rate Control; a Clinical Trial

Introduction: Treatment of rapid ventricular response arterial fibrillation (rapid AF) varies depending on the decision of the in-charge physician, condition of the patient, availability of the drug, and the treatment protocol of the hospital. The present study was designed aiming to compare IV digoxin and amiodarone in controlling the heart rate of patients presenting to emergency department with rapid AF and relative contraindication for first line drug in this regard.Method: In the present clinical trial, patients presented to the ED with rapid AF and relative contraindication for calcium channel blockers and beta-blockers were treated with either IV amiodarone or IV digoxin and compared regarding success rate and complication using SPSS version 22. P &lt; 0.05 was considered as statistically significant.Results: 84 patients were randomly allocated to either amiodarone or digoxin treatment groups of 42 (53.6% male). The mean age of the studied patients was 61.8 ± 11.14 years (38 - 79). No significant difference was present regarding baseline characteristics. The rate of treatment failure was 21.4% (9 cases) in amiodarone and 59.5% (25 cases) in digoxin groups (p &lt; 0.001). The mean onset of action was 56.66 ± 39.52 minutes (10 - 180) in amiodarone receivers and 135.38 ± 110.41 minutes (25 - 540) in digoxin group (p &lt; 0.001). None of the patients showed any adverse outcomes of hypotension, bradycardia, and rhythm control.Conclusion: Based on the findings of the present study, rapid AF patients with relative contraindication for calcium channel blockers or beta-blockers who had received amiodarone experienced both higher (about 2 times) treatment success and a more rapid (about 2.5 times) response compared to those who received IV digoxin

The Effects of Low Level 660nm Laser Irradiation on Pain and Teeth Hypersensitivity after Periodontal Surgery

Abstract: Introduction: Tooth pain and sensitization are the two main causes of discomfort after periodontal flap surgery. Effects of low level laser therapy for reducing pain have already been established; these kinds of lasers have been used for tooth desensitization as well. This controlled blind study sought to compare tooth pain and sensitization after 660nm laser irradiation in a split mouth and also in a control group after periodontal flap surgery. Methods: Forty patients were enrolled in this study. In these entire patients periodontal flap surgery was done in the upper anterior segment. In the test group, by tossing of a coin the left or right side was determined for laser irradiation, so central incisor, lateral incisor and canine were irradiated by swiping motion of 660nm laser (AZOR, Russia) 25mW, 4.5 J, and 3 min every other day starting one day after surgery; and in collateral segment a placebo probe was put to blind the patients. In the control group, dressing was used after surgery. One, 3, 5 and 7 days after surgery for both groups visual analog score (VAS) for tooth pain and sensitization were recorded for both sides in each patient. Results: In the laser group, both sides had lower VAS for pain than the control group (P&lt; 0.05) after the first day. There was no statistical difference in the laser group between laser irradiated, or non-irradiated segment and for sensitization between groups. Conclusion: Pain can be reduced after periodontal surgery by using low level 660nm laser therapy. Lower pain in both sides in the laser group may be the result of the spread of mediators and neurotransmitters secreted after laser irradiation, or may be because of scattered radiation in the collateral part

Early vs Late Coronary Angiography and Intervention Following Thrombolytic Therapy; a Cohort Study

Introduction: The precise time of using percutaneous coronary intervention (PCI) after fibrinolytic therapy for maximum efficiency and minimum side effects is still undetermined. Therefore, the present study was designed to compare the outcome of myocardial infarction (MI) patients who underwent surgical intervention (angiography and PCI) within 48 hours of thrombolytic therapy or after that.Methods: The present study is a prospective cohort study aiming to compare the occurrence of no-reflow phenomenon, unstable angina, bleeding during intervention, and one month major adverse cardiac outcomes (recurrent MI, need for repeating surgical intervention, and mortality) between MI patents undergoing surgical intervention within the first 48 hours of or after 48 hours of thrombolytic therapy.Results: 90 patients with the mean age of 54.97 ± 10.54 were studied (86.67% male). 50 (56%) patients underwent surgical intervention within 48 hours and 40 (44%) after that. The 2 groups were not significantly different regarding baseline characteristics. No-reflow phenomenon in the &lt; 48 hours group was about twice the &gt; 48 hours group (OR = 0.35; 95% confidence interval: 0.14 – 0.92; p = 0.03), other outcomes were not significantly different. No case of mortality was seen in the 1 month follow up.Conclusion: Based on the results of the present study, it seems that no-reflow phenomenon rate is significantly lower in patients undergoing surgical intervention after 48 hours of fibrinolytic therapy. The difference between the two groups regarding prevalence of major adverse cardiac outcomes was not statistically significant

Determinants of gastroesophageal reflux disease, including hookah smoking and opium use- a cross-sectional analysis of 50,000 individuals.

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common cause of discomfort and morbidity worldwide. However, information on determinants of GERD from large-scale studies in low- to medium-income countries is limited. We investigated the factors associated with different measures of GERD symptoms, including frequency, patient-perceived severity, and onset time. METHODS: We performed a cross-sectional analysis of the baseline data from a population-based cohort study of ∼ 50,000 individuals in in Golestan Province, Iran. GERD symptoms in this study included regurgitation and/or heartburn. RESULTS: Approximately 20% of participants reported at least weekly symptoms. Daily symptoms were less commonly reported by men, those of Turkmen ethnicity, and nass chewers. On the other hand, age, body mass index, alcohol drinking, cigarette smoking, opium use, lower socioeconomic status, and lower physical activity were associated with daily symptoms. Most of these factors showed similar associations with severe symptoms. Women with higher BMI and waist to hip ratio were more likely to report frequent and severe GERD symptoms. Hookah smoking (OR 1.34, 95% CI 1.02-1.75) and opium use (OR 1.70, 95% CI 1.55-1.87) were associated with severe symptoms, whereas nass chewing had an inverse association (OR 0.87, 95% CI 0.76-0.99). After exclusion of cigarette smokers, hookah smoking was still positively associated and nass chewing was inversely associated with GERD symptoms (all frequencies combined). CONCLUSION: GERD is common in this population. The associations of hookah and opium use and inverse association of nass use with GERD symptoms are reported for the first time. Further studies are required to investigate the nature of these associations. Other determinants of GERD were mostly comparable to those reported elsewhere

Diabetes Mellitus and Its Correlates in an Iranian Adult Population

The rising epidemic of diabetes imposes a substantial economic burden on the Middle East. Using baseline data from a population based cohort study, we aimed to identify the correlates of diabetes mellitus (DM) in a mainly rural population from Iran. Between 2004 and 2007, 50044 adults between 30 and 87 years old from Golestan Province located in Northeast Iran were enrolled in the Golestan Cohort Study. Demographic and health-related information was collected using questionnaires. Individuals' body sizes at ages 15 and 30 were assessed by validated pictograms ranging from 1 (very lean) to 7 in men and 9 in women. DM diagnosis was based on the self-report of a physician's diagnosis. The accuracy of self-reported DM was evaluated in a subcohort of 3811 individuals using fasting plasma glucose level and medical records. Poisson regression with robust variance estimator was used to estimate prevalence ratios (PR's). The prevalence of self-reported DM standardized to the national and world population was 5.7% and 6.2%, respectively. Self-reported DM had 61.5% sensitivity and 97.6% specificity. Socioeconomic status was inversely associated with DM prevalence. Green tea and opium consumption increased the prevalence of DM. Obesity at all ages and extreme leanness in childhood increased diabetes prevalence. Being obese throughout life doubled DM prevalence in women (PR: 2.1; 95% CI: 1.8, 2.4). These findings emphasize the importance of improving DM awareness, improving general living conditions, and early lifestyle modifications in diabetes prevention